getURL

Obtain, in String form, the URL for an entry in this JAR. Note that for
JARs nested in WAR files, the Tomcat specific war:file:... form will not
be used, rather the jar:jar:file:... form (that the JRE does not
understand will be used). Note that this means that any code using these
URLs will need to understand the jar:jar:file:... form and use the
JarFactory to ensure resources are accessed correctly.